1. Field of the Invention
The present invention relates to an integrated twist-grip switch for the shifting of bicycle gears, such as multi-speed hubs or dxc3xa9railleur shifts.
2. Description of the Related Art
Twist-grip switches for the control of bicycle gears are generally preassembled and mounted on the bicycle, i.e., pushed onto the handlebar tube, in the preassembled state. The twist-grip switch is then adjusted and fixed on the handlebar. The attachment to the handlebar is usually carried out by a clamping device.
In a preassembled twist-grip switch, a plurality of switch components are assembled together, and a locking connection is often used, which is not releasable after the preassembled twist-grip is mounted on the handlebar tube.
However, before installation of the preassembled twist-grip switch on the handlebar tube, it is possible for the still releasable locking connection to loosen, thereby breaking apart the preassembly of the components and incurring an increase in the outlay in terms of assembly. For this reason, it is desired to make the locking connection more reliable.
It is an object of the present invention to increase the reliability of the fixing of the components in a preassembled unit. The object is achieved by a clamping clip. In addition to its function of fixing the switch on the handlebar tube, the clamping clip also prevents the locking connection from becoming loose.
Furthermore, switch housings constructed predominantly from plastics have problems of space in the region of a switch housing. Locking devices are located in the region of the housing to fix the components of the switch in the preassembled state. Moreover, it is necessary to clamp the switch on the handlebar tube. The plastic material alone does not have the strength necessary for this purpose, or creeping processes of the material are detrimental to a permanently reliable fixing of the switch on the handlebar tube. The clamping clip arranged in the housing solves the problem of connecting the switch to the handlebar tube. However, the strict separation between the interlocking of other components of the switch with the housing and the clamping of the switch to the handlebar requires a greater space requirement.
According to the present invention, the problem of space is solved by combining two functions and direct interaction between the respective operating elements. That is, the present invention includes radially elastic tongues arranged on the bearing tube which are equipped at the end with a locking profile to form a nonrotatable and nondisplaceable positive connection with a counterprofile on the switch housing. The twist-grip part, the winding reel, and also the switch housing together with the switch mechanism may be lined up via these elastic tongues for forming a preassembly which is mountable onto the bearing tube. This preassembly is secured against inadvertent breaking apart by the snap connection between the bearing tube and switch housing. The number of components of the twist-grip switch needed for the final mounting step on the handlebar is thereby markedly reduced. The arrangement of the clamping clip in the inside diameter of the switch housing with the accompanying screw allows the complete twist-grip switch to one piece ready for mounting. Tightening the screw on the clamping clip ensures a secure fit of the twist-grip switch, including a grip end piece, on the handlebar. The bearing tube or the twist-grip part together with winding reel may be demounted again or uncoupled from the switch housing only after the removal of the clamping clip. To ensure a play-free fit on the handlebar, the inside diameter on the bearing tube and on the grip end piece has a correspondingly narrow dimension or tolerance. Controlled deformation of the inner region may also be used to eliminate the sensitivity to tolerance. Thus, the inner surface of the bearing tube may include at least a part region, preferably axially adjacent to the elastic tongues, having a shape which is not circular, but oval or polygonal to achieve a play-free fit during adaption to the round handlebar cross section. The same play-free fit may be achieved when this bearing tube inner region is equipped with narrow elevations which run essentially in the axial direction which undergo deformation during mounting and then fit firmly. Perforations may be arranged on the bearing tube in the region of the overlap of the grip end piece so that when the grip end piece is being attached material of the grip end piece projects into the inside diameter of the bearing tube. During assembly of the preassembly onto the handlebar, the material projecting into the inside diameter experiences a deformation and is pressed on.
The bearing tube is prolonged in the direction of the grip end piece. The grip end piece is fixed to the bearing tube by a chemical overmolding connection. In contrast to the prior art described, the bearing tube of the present invention is not connected fixedly in terms of rotation to the elastic twist-grip part and the winding reel. Rather, the bearing tube serves as a mounting for these and forms, with the fixed intermediate ring, the necessary axial abutment for the twist-grip part connected fixedly in terms of rotation to the winding reel.
Other objects and features of the present invention will become apparent from the following detailed description considered in conjunction with the accompanying drawings. It is to be understood, however, that the drawings are designed solely for purposes of illustration and not as a definition of the limits of the invention, for which reference should be made to the appended claims. It should be further understood that the drawings are not necessarily drawn to scale and that, unless otherwise indicated, they are merely intended to conceptually illustrate the structures and procedures described herein.